Study "digestive system", a flashcard deck on FORKSAI.
Define digestion and distinguish between its mechanical and chemical forms.
Digestion is the process of breaking down food into forms that cell membranes can absorb. Mechanical digestion breaks down large pieces of food without altering its chemical composition, while chemical digestion uses enzymes to break down food molecules into simpler building blocks.
Which of the following is NOT a primary function of the digestive system? A) Ingestion B) Secretion C) Filtration D) Absorption
C) Filtration. The primary functions of the digestive system include ingestion, secretion, propulsion, digestion, absorption, and defecation, but not filtration.
What is peristalsis and what role does it play in the digestive system?
Peristalsis refers to the rhythmic contractions of smooth muscle that serve as a form of propulsion in the digestive system. It moves food through the alimentary canal.
Name the three pairs of salivary glands and state which gland secretes the largest percentage of total saliva.
The three pairs of salivary glands are the parotid glands, submandibular glands, and sublingual glands. The submandibular gland secretes the largest percentage, accounting for 65-70% of total saliva.
How is salivation primarily controlled, and which nervous system division is largely responsible?
Salivation is primarily controlled by the parasympathetic system in a reflex arc. Sensory stimuli communicate to the salivary nucleus in the brainstem, leading to parasympathetic fibers stimulating the salivary glands to release saliva.
Which parts of the pharynx are considered part of the alimentary canal, and what is their primary function?
Only the oropharynx and laryngopharynx are part of the alimentary canal. Their primary function is the propulsion of food in the form of swallowing.
What is deglutition, and what structures are involved in this process?
Deglutition, or swallowing, is a specialized type of propulsion that pushes a bolus of food from the oral cavity through the pharynx and esophagus to the stomach. It relies on the coordinated action of the tongue, soft palate, pharynx, and esophagus.
In which parts of the alimentary canal is motility due to skeletal muscle, as opposed to smooth muscle?
Motility is due to skeletal muscle in the oral cavity, pharynx, superior portion of the esophagus, and the last portion of the large intestine. In the rest of the alimentary canal, motility is the work of smooth muscle.
How does the nervous system regulate digestive processes?
The nervous system regulates digestive processes through the Autonomic Nervous System (ANS). The sympathetic system generally inhibits digestive processes, while the parasympathetic system stimulates them.
What are gastric pits, and what type of cells are found between them in the stomach mucosa?
Gastric pits are heavy indentations in the stomach mucosa. Between these pits, columnar cells are found, which secrete mucus to protect the stomach cells from its own secretions.